1. Field of the Invention
The present invention relates to a combination structure of frame and motor hub, and more particularly, to a combination structure of frame and motor hub adapted for an electric bicycle.
2. Description of Related Art
Conventionally, the wheel axle of an electric bicycle is provided with a motor hub at the center of the axle for driving forward the electric bicycle, where both sides of the motor hub are pivotally arranged in between a fork assembly and are fastened and secured thereto with nuts. However, when assembly of the motor hub or replacement thereof, complex steps are required to manually detach the nuts from both sides of the motor hub so as to replace or maintain the same. Namely, when maintenance staff want to assemble or replace the motor hub, the nuts at both sides of the hub need to be tightly fastened manually so as to attach the hub; or on the other hand, the nuts need to be manually unfastened so as to detach the same from the bicycle frame. Such manual work is rather inconvenient, and the fastening or unfastening of the nuts is indeed time and labor consuming.
Further, the frame-fastening holes located at two sides of the conventional motor hub have downward U-shaped openings, where nuts are tightened toward the frame and the axle so as to secure the same. However, when disassembling the motor hub, suppose the axle of the motor hub escape suddenly from the U-shaped openings, and thus the motor hub falls and is damaged or even hurts people. This will add inconvenience to maintenance staff.
In view of the above, an innovative combination structure of bicycle frame and motor hub has been developed, through persistent experiments, so as to improve convenience and safety during maintenance or assembly of the electric bicycle.